1. Field of the Invention
The present invention relates to an optical unit comprising an optical element and a support member for supporting the optical element and a method for manufacturing the optical unit.
2. Description of the Related Art
An optical disc has been used as a medium for storing a large volume of data. In order to storing information in a high density and retrieving that information reliably, each component of an optical pickup device should be mounted so precisely. For this purpose, JP H04-113521 A discloses a technology for adjusting a thickness of adhesive provided between an objective lens and a holder supporting the objective lens and thereby controlling a tilting of the object lens. With this technology, however, a local thickness variation of the adhesive may result in further tilting of the objective lens. In accordance with JP H08-161755 A, a bimetal or deformable member is mounted between the objective lens and the holder for holding the objective lens, so that the deformable member is deformed by an application of heat energy to control the tilting of the objective lens. Likewise, JP H08-180422 A and JP H09-161755 A propose a method in which a support member made of shape-memory alloy or thermosensitive material is mounted between the objective lens and the holder for holding the objective lens and a laser is irradiated onto a part of the support member to recover the original shape for the adjustment of the tilting of the objective lens. The techniques disclosed in the above-described prior art documents JP H08-161755 A, JP H08-180422 A and JP H09-161755 take more time to control the tilting of the objective lens in order to prevent a possible deformation of the holder which might otherwise be caused by an external force applied at the adjustment. Also, the support member is needed between the lens and the holder, which further complicates the structure.